Lamellar ichthyosis

Question 1

What is the inheritance pattern of lamella ichthyosis?

Answer 1

Autosomal recessive

Question 2

Which gene is associated with lamella ichthyosis and where is it located?

Answer 2

Transglutaminase 1 (TGM1) gene on 14q11

Question 3

What are the prenatal diagnostic methods for lamella ichthyosis?

Answer 3

Chorionic villus sampling (CVS)/amniocentesis - YGM1 gene mutation of linkage analysis in families where molecular defect is known.
OR fetal skin biopsy at 22 weeks

Question 4

What is the incidence rate of lamella ichthyosis?

Answer 4

Less than 1:300,000

M = F

Question 5

At what age does lamella ichthyosis typically present?

Answer 5

Birth

Question 6

What is the pathogenesis of lamella ichthyosis?

Answer 6

Heterogeneous mutations in the TGM1 gene interfere with normal cross-linking of structural proteins in the protein and lipid envelope of the upper epidermis leading to
defective cornification and desquamation

Question 7

What are the key skin features of a newborn with lamella ichthyosis?

Answer 7

Collodion baby appearance, ectropion, eclabium, generalized erythroderma

Question 8

What complications are newborns with lamella ichthyosis at risk for?

Answer 8

Secondary sepsis, hypernatremic dehydration

Question 9

What are the skin features of a child or adult with lamella ichthyosis?

Answer 9

Generalized large, dark, platelike scale increased in flexures, hypohidrosis with heat intolerance, erythroderma, ectropion, palmoplantar keratoderma

Question 10

What hair condition is associated with lamella ichthyosis?

Answer 10

Scarring alopecia

Question 11

What nail condition is observed in lamella ichthyosis?

Answer 11

Secondary dystrophy with nail fold inflammation

Question 12

List some differential diagnoses for lamella ichthyosis.

Answer 12

• Epidermolytic hyperkeratosis
• X-linked ichthyosis
• Congenital ichthyosiform erythroderma
• Netherton syndrome
• Trichothiodystrophy

Question 13

What investigations are used for diagnosing lamella ichthyosis?

Answer 13

• Skin biopsy for transglutaminase-1 expression
• Light microscopic hair examination
• Sepsis workup

Question 14

What is the management for newborns with lamella ichthyosis?

Answer 14

• Transfer to neonatal intensive care unit
• Monitor fluids and electrolytes
• Emolliation
• High-humidity chamber

Question 15

What treatments are recommended for children and adults with lamella ichthyosis?

Answer 15

• Retinoids
• Emolliation
• Avoiding strenuous activity and overheating

Question 16

What is the prognosis for individuals with lamella ichthyosis?

Answer 16

Severe involvement throughout life; normal life span

Question 17

WHen is the collodion membrane shed?

Answer 17

First few days to weeks of life